Wednesday, March 13, 2013

Chlorination for An Old Well

I have some questions about chlorinating my water.

I've had this well almost 30 years. I don't know how old it is, but there was an old wooden elevated storage tank and a fallen windmill next to the well when I bought the land. It is about 125 feet deep.

It has never made us sick and people were drinking from this well long before we bought the land.  The well is in the middle of our horse paddock next to the barn.  Not a good location, but this is how the farm was set up back in the 1800s.

We are wondering what we would need to do to put a chlorinator in the loop to ensure we don't get any fecal related bugs.  We do have iron. It used to discolor the water before we got a water softener and started using the salt that is formulated to get the iron out.  But, we still get the dark rings in the commodes.

I don’t know if we can chlorinate the water as it goes into the holding tank or not. That would be ideal since I can put the chlorinator in the small building we have built around the well.

I see your chlorinators are rated in outputs of gallons per day. What does “output of 0.5 to 10 gal. per day” mean?  I use more than that.  Sometimes I will use several hundred gallons to fill water troughs or water gardens.


Hello Ray,

You can most definitely add chlorination to eliminate bacteria and prevent possible contamination.  It should also greatly help you with your issues of dark rings forming in the toilet, if it is an issue with iron or iron-related bacteria, although additional iron filtration may be desired after the storage tank and before your water softener.

Adding the chlorine prior to the concrete holding tank would be ideal- not only would you be able to install it in the convenient location of the small building, but it would give you the most contact/retention time in order to disinfect the water.

We would recommend this 220 volt Stenner chlorinator pump, which you could wire directly to your well pump, and feed the supply line of the injection tubing right into the line prior to your 100-gallon storage tank.  The system is adjustable, easy to install, and a great value for the price.

Regarding the output of the pumps:  “Per day” in this case actually means: per 24 hours of the pump running.  This is because the chlorinator pump turns on and off with the well pump, so the pump is set and sized based on 24 hours of continual use.  In reality, your pump would be more likely to run a total of 24 hours in about a week or several days.

Additionally, 0.5 to 10 gal per day refers not to your flow of water, but to the flow of fluid being injected by the pump.  It doesn’t take very much chlorine solution to treat water, especially when you’re using it as a preventative measure.  So if for example your water is flowing into the concrete tank at around 10 to 15 gallons per minute, we would help you with a calculation to know exactly what to set the pump at, but it would most likely be set to somewhere around 3 to 7 gallons per day, or around the halfway setting on the pump dial. 

Here’s a diagram showing the chlorinator before the storage tank:

You could also, as an option, remove the chlorine afterwards using carbon filtration, placed prior to the water softener.  Please let us know if you have any questions regarding this.